re: "better"
Tk is less encumbering than Qt, and in many ways easier to use, but it is not quite as comprehensive in some respects and it often results in software that looks a little "dated". In addition to be less encumbering, it offers a bit more flexibility in terms of how it is used -- though I suppose one could call that a "less encumbering" benefit as well.
I don't know what you mean about availability. Tk is available all over the damned place.
QUOTE: GTK+ ? Good enough, I guess, but since I use KDE desktop, the 1st choice for me is obviously Qt
GTK+ is everywhere. It's almost certainly already on your system, whether you use KDE or GNOME for your primary GUI environment. GTK itself did not start out as GNOME, by the way -- the G stands for GIMP (the image editor). I find GTK marginally less offensive than KDE because its implementation is a touch less "beefy" (that is: big and heavy), and it's a lot harder to avoid GTK than KDE so unless I'm running a GUI-less system I almost certainly have GTK on it and almost certainly don't have any Qt stuff on it anyway.
QUOTE: Mono?
Yeah . . . I'm not using Mono, either.
QUOTE: Java?
Don't get me started on Java. The simple point is that I'm not a fan. Java is not at all portable: it only really runs on one "machine" (the JVM), and is thus only as portable as that -- and the JVM is a heinous pain in the neck to install and maintain on many systems, to say nothing of startup slowness and other annoyances. About the only place Java really makes sense these days is long-running heavy processes on servers, where the user has no clue what's happening on the back end and the optimizing capabilities of the runtime start coming into play.
QUOTE: Vala? Give me a break!
Yeah . . . I wasn't aware anyone took it seriously. (Okay, I kid -- slightly.)
QUOTE: The problem I was going to solve (natural language processing) seemed computationally intensive from the very beginning, which excluded interpreted languages.
Wait -- what? The GUI framework you use should have pretty much nothing to do with computationally intensive back-end code. Hell, given what you just said, I'd think you'd want to write the heavy-lifting code as a library, then just slap a thin GUI veneer over it for end-user operation.
